Continuously operating filtering arrangement



J. FURSTENBERG ETAL CONTINUOUSLY OPERATING FILTERING ARRANGEMENT Filed Oct. 18, 1968 Dec. 15, 1970 2 Sheets-Sheet 1 NOE I... :Zm {M U k 2 mi V MW "m CONTINUOUSLY OPERATING FILTERING ARRANGEMENT Filed OCt. 18, 1968 15, 1970 J. FURSTENBERG.

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United States atent 3,546,852 Patented Dec. 15, 1970 3,546,852 CONTINUOUSLY OPERATING FILTERING ARRANGEMENT Joachim Fiirstenberg, Aichelberg, near Esslingen, and Horst Kurrle, Stuttgart-Bergheim, Germany, assignors to LTG Lufttechnische Gesellschaft mit beschrankter Haftung, Stuttgart-Zutfenhausen, Germany Filed Oct. 18, 1968, Ser. No. 768,936 Claims priority, application Japan, Mar. 8, 1968, 43/ 14,726 Int. Cl. B01d 46/02 U.S. Cl. 55-341 6 Claims ABSTRACT OF THE DISCLOSURE Cut off threads and other impurities in the air surrounding a plurality of knitting machines are sucked off through a suction chamber in which two filters are located. Airflow guide means in the chamber are manually shifted to connect one or the other filter between the inlet and the outlet of the suction chamber so that at any time, one filter is operative, and the other filter is unused and can be cleaned and removed, permitting a continuous filtering of the air surrounding the knitting machines.

BACKGROUND OF THE INVENTION It is known to provide air exhausting and filtering apparatus for a number of knitting machines, particularly for circular knitting machines on which seamless hose is made. Knitting machines of this type have at least one cutting means for cutting ofl change ends and reinforcing threads, and each cutting means is provided with an air nozzle for sucking off the thread ends.

After a period of use, the filter is clogged by the cutoff thread ends and other impurities, so that it is necessary to remove the thread ends. It is desirable to clean the filter without interruption or slowing down of the knitting operation.

SUMMARY OF THE INVENTION It is one object of the invention to provide a continuously operating filtering arrangement, particularly for a number of knitting machines, by which thread ends and other impurities can be continuously removed from the air without disturbing the operation of the knitting machines during the cleaning of the filtering arrangement.

Another object of the invention is to provide a continuously operating filtering arrangement of very simple and inexpensive construction.

Another object of the invention is to provide a continuously operating filtering arrangement for a large number of knitting machines, for example for 50 to 100 circular knitting machines.

Another object of the invention is to provide a filtering arrangement which permits the cleaning of filters by a very simple operation by unskilled persons.

With these objects in view, one embodiment of the invention is applied to apparatus producing impurities in the surrounding air, for example a number of circular knitting machines on which seamless hose is being knitted, and thread ends cut off, and comprises suction pipe means, preferably having branch pipes with suction openings in the proximity of the knitting machines, respectively; a chamber having an inlet connected with the suction pipe means and an outlet connected with an exhauster so that air containing impurities is drawn through the suction pipe and the chamber; first and second filters located in the chamber; airflow guide means,

preferably in the form of a plate, mounted in the chamber for movement between a first position and a second position; and setting means for moving the guide means between the first and second positions.

In the first position of the airflow guide means, air is guided from the inlet through the first filter to the outlet of the chamber so that impurities are retained by the first filter, and in the second position, air is guided from the inlet through the second filter to the outlet, so that impurities are retained by the second filter.

Since only one of the filters is operative and blown through by air containing impurities, such as thread ends, the other filter can be cleaned, and retained impurities and thread ends removed therefrom. The guide means can then be shifted to guide the flow of air through the clean filter rendering the other filter inoperative so that it can be cleaned.

Not only the thread ends cut off by cutting means can be removed from the air in this manner, but also the pneumatic draw-off means by which the finished hose knitted on a circular knitting machine is pulled down, can be provided with suction nozzles communicating with the suction pipe means of the apparatus of the invention.

Particularly if suction pipe means remove the air from a great number of knitting machines, it is very desirable and advantageous that the filtering apparatus of the invention continuously operates without requiring an interruption of the knitting operation, or of the air filtering operations during cleaning of a filter. It is also advantageous that the thread ends cut off on a great number of knitting machines are filtered and collected at a central filtering arrangement, and can be removed from the filters from time to time.

In the preferred embodiment of the invention, the guide means include a plate which is angularly displaced to render one or the other of the filters operative when the respective other filter is being cleaned. In some cases, an automatic setting apparatus for shifting the guide means from time to time between the two positions in which one or the other filter is operative is provided. A motor circuit with automatic timing means starting and stopping the motor alternately for rotation in opposite directions may be used.

In a preferred embodiment of the invention, the suction chamber has an inlet chamber and an outlet chamber separated by a horizontal partition. The airflow guide means includes a guide plate dividing the inlet chamber into first and second inlet chamber portions, which communicate through openings in the partition wall with the first and second filters which are located in the outlet chamber.

In one position of the guide plate, the inlet of the chamber is connected with the first inlet chamber portion and with the first filter, while in the other position of the guide plate, the inlet of the chamber is connected with the second inlet chamber portion and with the second filter, while the first filter and the first inlet chamber portion are separated from the air inlet.

It is advantageous to provide another guide plate in the outlet chamber dividing the same into first and sec ond outlet chamber portions in which the first and second filters are, respectively, located. The second guide plate separates the inoperative filter from the outlet of the outlet chamber so that no air current surrounds the inoperative filter during the cleaning of the same.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of spe- 3 cific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic plan view illustrating a filtering arrangement of the invention applied to a number of knitting machines arranged in two parallel rows;

FIG. 2 is a schematic elevation illustrating the arrangement of FIG. 1;

FIG. 3 is a front view of a filtering apparatus according to the invention, provided in the arrangement of FIGS. 1 and 2, and drawn to enlarged scale; and

FIG. 4 is a sectional view taken on the line IVIV in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIGS. 1 and 2, the filtering arrangement 1 includes a plurality of branch pipes 3 which communicate with a main suction tube 4 disposed between two rows of circular knitting machines 9 for knitting seamless hose, each of which has cutting means for cutting off thread ends, not shown. For the sake of simplicity, only four knitting machines 9, and four branch pipes are shown, but it is to be understood that a great number of knitting machines is arranged in two rows, as indicated by the two chain lines between the illustrated knitting machines 9 in FIG. 1.

The main suction pipe 4 opens into the inlet of a filter casing 2 which has an outlet connected by an outlet pipe 7 with an exhauster 6 which sucks air from the proximity of the knitting machines 9 through suction nozzles on the ends of branch pipes 3, the main suction pipe 4, the chamber in the filter casing 2, and through outlet pipe 7, and blows the air through an air guide means 8 which is connected to further ducts for removing the air out of the hall in which the knitting machines and the filtering arrangement are located.

The cutting means of the knitting machines 9 by which the thread ends are cut off are of conventional construction and not illustrated. The knitting machines 9 are also provided in known manner with a draw-off device for pulling down the knitted seamless hose: Branch pipes, not shown, and connecting the draw-off device with the main suction pipe, may also be used for this purpose and apply suction to the knitted fabric. Suction applied by said further branch pipes to the knitted fabric tensions the same during the knitting operation, and also serves for the pneumatic transport of the knitted hose to a storage place in known manner.

The filtering apparatus is illustrated in greater detail in FIGS. 3 and 4. In box-shaped casing 10, a horizontal partitioning wall 14 forms an upper inlet chamber 11 and a lower outlet chamber 12. The main suction pipe 4 is secured by a flange to an inlet opening in the top wall of the casing, and opens into the inlet chamber 11, while the outlet pipe 7 has a flange secured to a corre sponding outlet in the bottom wall 15. The inlet and outlet of the chamber within casing are aligned in vertical direction.

Partition wall 14 has two symmetrically arranged openings 16 and 17 to which air-permeable filter bags 19 and 20 are secured so that air flowing through openings 16 or 17, and through filter bags 19 or 20, is cleaned of thread ends which remain in the filter bags. The filter bags may consist of a suitable filtering material, preferably a woven fabric which is impermeable to the passage of impurities, such as thread ends, but permits the passage of air moved by the exhauster 6.

A shaft 33 passes through the top and bottom walls, and also through the partition wall 14 of casing 10. The upper portion of shaft 33 carries a guide plate 22, and the lower portion of shaft 33 carries a guide plate 34. A handle 36 is secured to a portion of shaft 33 projecting upward from the top plate of the casing, and can be operated to angularly displace guide plate 22 between the position 23 shown in solid lines and the position 24 shown in chain lines in FIG. 4 and guide plate 34 between corresponding positions.

Guide walls 29, 30, and other guide walls 31 and 32 are secured to opposite walls of casing 10 in the inlet chamber 11, and limit the angular movement of guide plate 22. Corresponding guide walls are provided in the lower outlet chamber 12, and co-operate with guide plate 34 to limit movement of the same in two positions corresponding to the positions of guide plate 22.

Guide plate 22 forms, in the inlet chamber 11, a first inlet chamber portion 40 and a second inlet chamber portion 41.

In position 23 of guide plate 22, the inlet of casing 10 to which suction pipe 4 is connected is located in the inlet chamber portion 40. In the second position 24 of guide plate 22, the inlet communicating with suction pipe 4 is located in the second inlet chamber portion 41.

correspondingly, the outlet in bottom plate 15 connected with outlet pipe 7 is located in one position of guide plate 34 in a first outlet chamber portion 35, and in the other position of guide plate 34, in outlet chamber portion 37.

The front wall of casing 10 is provided at the level of the inlet chamber portions 40 and 41, respectively, with access openings respectively closed by closure lids 44 and 45 having handles 46 and 47, respectively, and being mounted on horizontal hinge pins 42 and 43. When either closure lid is opened, the openings 16 or 17 and the filter bags 19 or 20 are accessible.

The filtering arrangement is operated as follows:

In position 23 of guide plate 22, the air is sucked from the main suction pipe 4 into the first inlet chamber portion 40 and through opening 16 into the interior of filter bag 19. After passage of the air through the fabric of the filter bag 19, by which thread ends are retained, the air flows into the outlet chamber 12 and through outlet pipe 7 to exhauster 6.

When it is desired to clean filter bags 19, guide plate 22 is turned to position 24 so that the air to be cleaned flows through the second inlet chamber portion 41 and filter bag 20 into the outlet chamber 12. Closure lid 44 can now be opened, and the thread ends removed from the interior of the filter bag 19 whose edge is secured to the rim of opening 16 so that the interior of the filter bag is accessible. By shifting the guide plate 22, one of the filter bags 19 and 20* is alternately rendered inoperative and can be cleaned without disturbing or interrupting the filtering or knitting operations.

In the above description, no reference was made to guide plate 34, since the same may be omitted and nevertheless a desired continuous filtering operation carried out. However, guide plate 34, turning with guide plate 22, separates the inoperative filter bag from the outlet of casing 10 communicating with outlet pipe 7, so that no air currents flow around the respective inoperative filter bag 19 or 20, facilitating the cleaning of the same.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of filtering arrangements differing from the types described above.

While the invention has been illustrated and described as embodied in a continuously operating filtering arrangement for a number of circular knitting machines, including two alternately operative filter means, it is not in tended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Continuously operating filtering arrangement comprising apparatus producing impurities in the surrounding air; suction pipe means having suction openings in the proximity of said apparatus; a closed housing having first and second pairs of opposed side walls and a pair of first and second end walls; a partition extending across said housing intermediate and spaced from said first and second end walls to define with the same and said side walls, first and second chambers, respectively, said partition being provided with first and second partition openings; first and second filter bags positioned in said second chamber and being sealed at the open ends thereof to said partition about said partition openings; said housing including an inlet into said first chamber in said first end wall and an outlet from said second chamber in said second end wall, said inlet and outlet being axially aligned along an axis located between said first and second partition openings; a pair of first spaced stop walls extending from one side Wall of said first pair of opposed sidewalls between said first end Wall and said partition, and projecting into said first chamber about said inlet; a corresponding pair of second spaced stop walls extending from the other side wall of said first pair of opposed side walls between said first end wall and said partition, and projecting into said first chamber; a vane mounted for rotation between a first position abutting one of said first stop Walls and the opposed one of said second stop walls, and a second position abutting the respective other stop Walls for guiding in said first position air from said inlet through said first filter bag to said outlet while separating said inlet from said open end of said second filter bag, and for guiding in said second position air from said inlet through said second filter bag to said outlet while separating said open end of said first filter bag from said inlet; setting means connected with said vane for moving the same between said first and second positions; and access means in said side walls for providing access to said filter bags in said housing whereby any one of said filter bags can be cleaned While air fiows through the respective other filter bag, and impurities are retained by the same said suction pipe means being connected to the inlet of the housing and means for causing suction in said suction pipe means.

2. Filtering arrangement as claimed in claim 1 wherein said access means include access openings which open into said first chamber adjacent said open ends of said first and second filter bags, respectively, and covers for closing said access openings.

3. Filtering arrangement as claimed in claim 1 wherein said apparatus includes a plurality of knitting machines producing said impurities in the air; and wherein said suction pipe means include a main suction pipe and branch pipes opening into said main suction pipe and having suction nozzles forming said suction openings.

4. Filtering arrangement as claimed in claim 1 including a second vane located in said second chamber and secured to said vane for rotational movement therewith, said second vane separating in said first position said second filter bag from said outlet, and separating in said second position said first filter bag from said outlet so that no air flow passes the filter bag Which is to be cleaned.

5. Filtering arrangement as claimed in claim 4 wherein said vanes are located in a common plane, and are connected with said setting means and together turnable by said setting means about an axis located in said plane.

6. Filtering arrangement as claimed in claim 5 wherein said setting means include a shaft passing through said first and second chambers and through said partition, and a handle outside of said housing secured to said shaft; and wherein said vanes are secured to said shaft and are turned together by operation of said handle.

References Cited UNITED STATES PATENTS 1,048,477 12/1912 Allington 419 1,455,116 5/1923 Lumley 55309 1,509,912 9/1924 Stebbins 55304 1,842,316 1/1932 Coulter 55258 1,974,952 9/1934 Eiben 55341 3,097,512 7/1963 Moyer 66140 3,332,218 7/1967 ODell 55303 3,373,545 3/1968 Christianson 55--302 3,402,530 9/1968 Agnon 55350 FOREIGN PATENTS 622,413 11/1935 Germany 55341 412,659 11/1966 Switzerland 19-107 FRANK W. LUTIER, Primary Examiner BERNARD NOZICK, Assistant Examiner US. Cl. X.R. 

